Better zone drawing

[le-jeu]

Current UI for drawing zone polygon is a die&retry experience. Some usual features are expected from users to avoid painful drawing:

• undo last point (simple)
• edit zone shape (complex)

Current solution is simple but offers the minimal feature for drawing. More advance features (if desirable) can also be done using external libraries like leaflet.draw (used for drawtool), leaflet lasso...

Related #200

[cloudkucooland]

I'm not opposed to this, and if someone wants to work on it, great. The current method was "how quickly can I prove concept."

My question is, are zones actively used? Do we want to invest a lot of work into an edge feature that no one actually uses. I've not checked the server data to see if there are actual zones set up. I should do that before I spout off, shouldn't I?

[le-jeu]

Autodraws give good use cases for zone since it allows to restrict the draw to a geographical zone instead of the screen (smaller of far bigger). [Set marker/link to zone] paired with the Filter feature also provide bulk assignment/color/state changes This may be a convoluted usage of zone that was logical zone only at first (matching in fact the polygon selection issue)